This invention relates to a method and an apparatus for shaping a dough piece, and in particular to a method and an apparatus for shaping a bar-like dough piece into a bent one.
It has been proposed to use a bending machine to modify a bar-like bread dough piece into a bent, e.g., an M-shaped, one.
Examples of the conventional bending machines are disclosed in Japanese Patent Early-Publications Nos. 48-96779 (Itoh) and 5-316923 (Yamazaki et al.), and Japanese Utility Model Early-Publication No. 48-31292 (Kuroha).
Itoh discloses a bending machine to modify a bar-like bread dough piece into an M-shaped one. The machine includes a conveyor for conveying the bar-like piece along a direction that is orthogonal to the length of the bar-like piece, and a bending mechanism located at the end of the conveyor. The bending mechanism includes a stopper for stopping the progress of the center portion of the bar-like piece on the conveyor, and a pair of brakes for stopping the progress of both ends of the bar-like piece. Above the conveyor, the bending mechanism also includes a pair of ratchet wheels, which has teeth for pushing the portions to be bent, which wheels are located between the center portion and both ends of the bar-like piece. The ratchet wheels rotate around a rotary shaft that extends the length of the bar-like piece in such a way that the teeth of the ratchet wheels contact and push the corresponding positions of the bar-like piece on the conveyor in the traveling direction. When the teeth of the ratchet wheels push the bent portions of the bar-like piece on the conveyor in the traveling direction, the center portion of the bar-like piece is stopped by the stopper and both ends of it are stopped by the brakes. Therefore, the incoming bar-like piece on the conveyor is formed into an M-shaped one by the bending mechanism.
This forming process, however, is unreliable, since each tooth of the ratchet wheels supports the corresponding bent portion of the bar-like piece only by point contact. Further, the rotary teeth of the ratchet wheels tend to scratch the M-shaped piece.
To remove these problems involved in the ratchet wheels, Yamazaki proposed to replace the ratchet wheels in Itoh with a pair of pivotaling rods, which extend in the direction of the thickness of the bar-like piece on the conveyor. In that process, the pivoting rods fall on the relevant positions of the bar-like piece in such a way that each pivoting rod supports the bar-like piece through a line contact. Once the bar-like piece has been formed into an M-shaped one, the pivoting rods pivot away from the M-shaped piece opposite the direction the conveyor is travelling.
Besides what Yamazaki has proposed, Kuroha proposed a movable damper which moves on the conveyor faster than does the conveyor, instead of the ratchet wheels of Itoh. Kuroha also proposed a detector for detecting the position of the dough on the conveyor to control the movable damper based on the signal from the detector.
Unfortunately, Yamazaki and Kuroha have difficulty in producing a symmetrical and well-balanced M-shaped piece. In particular, if the continuously fed bar-like pieces include undesired varying sizes, this difficulty increases. Thus, bread products that have been fermented and baked have a non-uniform shape.
Therefore, it is advantageous to provide an apparatus and a method to accurately change a bar-like dough piece into a bent and shaped one.
The present invention addresses the aforementioned problems by providing an apparatus for bending a bar-like dough piece extended along its length into a predetermined form. The apparatus comprises conveying means for continuously conveying bar-like dough pieces thereon in a traveling direction that is orthogonal to the length of each bar-like dough piece; bending means for bending each incoming bar-like dough piece symmetrically or asymmetrically with respect to the center of the length of the incoming bar-like dough piece; and replacing means for replacing at least one of the relationships of the relative dispositions in the length of the bar-like dough piece of the bending means and the incoming bar-like dough piece with a predetermined relationship of a disposition relative to them.
In one aspect of this invention, the predetermined relationship is determined so that the bending means bends the bar-like dough piece with a load substantially centrally located in the length of the bar-like dough piece. If this bar-like dough piece is to be further bent symmetrically with respect to the center of it, the predetermined relationship may also be determined so that the bending means bends the bar-like dough piece with loads substantially symmetrically located respect to the center of the bar-like dough piece, wherein the substantially symmetrically located loads are orientated inversely with respect to the substantially centrally located load. The resulting bent dough piece takes, e.g., an M-shape.
In another aspect of the invention, the predetermined relative position is determined so that the bending means bends said bar-like dough piece with an off-center load in respect to the center of the length of said bar-like dough piece. If this bar-like dough piece is to be further bent asymmetrically with respect to the center of it, the predetermined relative position may also be determined so that the bending means bends said bar-like dough piece with loads asymmetrically located with respect to the center of the length of said bar-like dough piece, wherein the asymmetrically located loads are orientated inversely with respect to said substantially centrally located load. The resulting bent dough piece takes, e.g., substantially an M-shape.
The present invention also provides an apparatus for bending a bar-like dough piece extended in its length into a predetermined form. The apparatus comprises conveying means for continuously conveying bar-like dough pieces thereon in a traveling direction that is orthogonal to the length of the bar-like dough piece; a first pushing means for pushing the bar-like dough piece on a first position that is located in said length of said bar-like dough piece; a first aligning means for aligning said first position of the dough piece with the first pushing means; a second pushing means for pushing the bar-like dough piece on the second of two positions that are located on said length of the bar-like dough piece, wherein the forces of said second pushing means to be applied to the second of two positions of the bar-like dough piece are orientated inversely with respect to the force of said first pushing means to be applied to the first position; and a second aligning means for aligning the second positions of said dough piece with the second pushing means.
The apparatus preferably comprises means for temporarily holding the conveyed bar-like dough piece and means for detecting both ends of the length of the temporarily held bar-like dough piece. The first aligning means may align both detected ends at predetermined positions. They correspond to imaginary ends of both ends of the bar-like dough piece. The first position can be either substantially positioned centrally or off-center on the bar-like dough piece.
The apparatus may also comprise means for measuring the length of the bar-like dough piece based on both said detected ends. To more appropriately control the bending process, the apparatus preferably comprises means for determining the degree of the pushing with the second pushing means against the second positions of the dough piece based on the measured length of the bar-like dough piece, and means for controlling the actual degree to be pushed with the second pushing means against the second position of the dough piece based on said determined degree. The measured length of the bar-like dough piece can also be used for an alternative alignment of the first aligning means so that the first position is either substantially positioned centrally or off-center on the bar-like dough piece.
The present invention also provides a method for bending a bar-like dough piece having a length into a predetermined form. The method comprises the steps of:
(a) continuously conveying bar-like dough pieces in a traveling direction that is orthogonal to the length of each said bar-like dough pieces;
(b) determining a plurality of actual positions from which each said bar-like dough piece is to be bent on the length of said bar-like dough piece;
(c) substituting said determined actual positions with predetermined positions; and
bending each incoming bar-like dough piece at said predetermined positions symmetrically or asymmetrically with respect to the center of said length of said incoming bar-like dough piece.
Additional features, advantages, and objectives of this invention will be set forth in the description which follows and in part will be apparent from it, or may be learned by practicing the invention.